Suncor Energy (U.S.A.)—the Denver-based U.S. unit of Calgary, Alberta-based Suncor Energy Inc., which recently agreed to merge withPetro-Canada—currently has an agreement to sell Phillips 66-brand gas in Colorado, which expires in July 2013, according to the report. Terms of the deal were not announced.

"This agreement positions Suncor well to continue to provide quality fuels to our marketers and consumers under the Shell brand, the No. 1 selling gasoline brand in America," Steve Douglas, Suncor vice president for supply and marketing, said in a statement cited by the paper.

As part of the agreement, stations in Colorado will be reimaged to the Shell brand starting immediately until 2013, according to the report. Reimaging will begin at the 44 Suncor-owned stations, Suncor spokeswoman Lisha Burnett told the paper, adding during the transitions, the stations will sell both Shell- and Phillips 66-branded products.